Water and other non-carbonated beverages, and particularly sports drinks, are sold in individual servings in the form of deformable plastic bottles which are squeezable. Such bottles typically have a cap in the form of a pull open/push close type closure, or a flip to open cap, which typically provides a single fluid passage which is not vented. The lack of a vent in the closure causes the deformable container to collapse as a consumer draws a beverage from the container while drinking, due to a pressure differential that is created between the fluid and the exterior of the container, since the external pressure is higher as the exiting liquid causes the internal pressure to decrease. At some point during the drinking process, depending on the size of the container, no additional liquid can be withdrawn from the container until the pressure is equalized by stopping the drinking process and allowing air to rush in through the single fluid passage in the closure. This equalization can cause a reflux or backwash from the consumer's mouth into the container, which tends to contaminate the fluid in the container. Because of these problems, consumers frequently equalize pressure by holding the bottle away from the mouth and squeezing the deformable bottle in a series of squirts, with pressure equalization taking place between each squirt. This procedure often results in spills of the fluid, and results in the consumer drinking less than were it easier to dispense fluid.
Conventional fluid containers are sometimes vented, but the vent typically is part of the container itself, and not part of the closure. Vented closures intended for pouring are known, but are undesirable for use in non-pouring type closures in which fluid will not continuously pour out of the bottle when the bottle is tilted downwardly. Sports bottles are an example of a non-pouring type closure which are intended to be left open for quick drinks during an activity, and can be easily knocked over. In general, pouring type closures are not suitable for sports bottles and other deformable containers in which the liquid exits in spurts due to squeezing of the container and/or placing the user's mouth around the closure opening to draw liquid out of the container.
The manufacturing cost of closures used on sports drink containers and the like is critical. An increase of fractions of one cent can severely impact marketability by the closure manufacturer since consumers usually are focused on the sports beverage or supplier and are generally unwilling to pay more for the bottle and closure which contains the beverage. Likewise, it is very important that any closure should be compatible with existing bottling and assembly equipment and should be usable in connection with standard bottling and assembly processes. The types of closures proposed in the past have been incompatible with these requirements.
The choke hazard posed by relatively small parts and/or separable parts used for closures have caused concern. Small children have been endangered by chewing on closures until the parts became distorted and loose. This problem is particularly troublesome for pull to open and push to close type closures.
One solution to the choke hazard is to use hinged top closures which typically have larger size parts that are molded as one piece. However, these hinged closures can be difficult to open and orient for comfortable use. It is difficult on many hinged top closures to identify the latching area and/or for a user to apply force to the latch to open, because the machinery used to attach the closure to the bottle during filling and assembly requires that nothing protrude from the closure surface. Another concern with hinged top closures is the difficulty for many users to properly orient the closure for opening and use. It is natural for users to rotate the closure so the latch is facing them to facilitate pushing the closure open with the thumb. However, the open hinged cover then tends to align behind the thumb and opposite the consumer's nose when the container is raised to drink. This is an uncomfortable and undesirable condition.
One objective of the present invention is to provide an improved vented fluid container closure of the non-pouring type that is adaptable to a standard beverage container and which are easily adaptable to current beverage filling and processing equipment.
Another objective of the present invention is to provide an improved hinged top closure which allows for easy opening, comfortable use and reduced choke hazard.
A further objective is to provide structure which improves the venting operation, and the dispensing of liquid through a mouthpiece for convenient drinking from a container which can be repeatedly opened and closed.